Males of this species have a glowing violet-blue gorget and can be distinguished from Sapphire-bellied Hummingbirds (Lepidopyga lilliae) by their green bellies. Both sexes have a forked tail and females are whitish below. Sapphire-throated Hummingbirds inhabit mangrove edges, dry scrub, lighter woodlands, and coastal lowlands. Although individuals often feed at low flowers in semi-open areas, multiple individuals may gather in flowering trees during the height of blooming.